Metal rolling



J. B. TYTUS METAL ROLLING Sept. 4, 1928.

Filed April 9, 1925 Patented Sept. yAll, 192.8.

UNITEDy STATES PATENT OFFICE.

.TOEN n. fryfrus, or MInDLETowN, oHIo, AssIGNon To THE AMERICAN ROLLINGMILL com-PANY, or MInnLEToWN, oHIo, A CORPORATION or oIIIo.

METAL ROLLING.

Application mea April 9, 1925. serial No. 21,814.

My invention relates to processes for rolling hot metal and particularlyto continuous processes, wherein the metal piece is moved from one standof rolls to another 'without being given m'ore than one pass in eachstand.l

It is the object of my invention to provide a rolling mill which willproduce bye single reductions of afmetal 'piece in successive stands ofrolls,wa .product which has` not hitherto been practical to 'produce inthis manner. The product which I produce is a thin, flat piece of metal,such as iron and steel.

In the steel industry the terminology for the product of rolling millsis usually traceable to the kind of process by which the product h asbeen formed. Thus the product of a plate mill is called plate, and of ajobbing mill and sheet mill are called sheets and of astrip mill, theproduct is called a anything like as fine a gauge as the sheet mill,

and the strip mill cannot produce a material which is anywhere nearaswide as either a plate mill or a sheet mill.

The product which I produce by my mill and process is that which liesbetween the zone of possible production o n the plate mill of today. andthe usual production on the f sheet mill.

produce is made' `on'the iobbing mill, which is hand fed with heatedbars, which are iirst rolled single and then in pairs, the entireoperation being hand controlled, usually on two stands of rolls, nottandem, one forl roughing andone for finishing.

It is my object to make such material at,

a high rate of speed with minimum of labor, by a continuous process. v j

It is my object to provide an arrangement of furnace,'shearsl and millstands, together with feed-.tables 'intermediate' the several At thepresent time the product whichr Iy machine elements, which will resultin sufliclent supply of hot pieces of manageable llength 'to the rolls,lfor successive or continent.

I accomplish my object by that certain construction and arrangement; ofparts and that certain processing of the metal which will be hereinaftermore speciiically pointed out and claimed.

' In the drawing:

Figure 1 is a plan view partially in diagram of my de vlce. l

Fi re 2 is a sideielevation thereof.

In t e drawings I have `shown a furnace 1, in which are live rollers 2,that feed a metal piece which is long,"wide and thick throughthe'furnace. The furnace is operated so as to conserve the heat of thepiece during shearing, and the shears -3 are lo` cated at the exit end'of the furnace, so thatl -Y each piece as itis sheared off from thelong piece will have a substantially equal temperature to begin with.l

From the practical p. ointof view it is' found highly desirable y me toemploy in the rolling process of my new mill a single piece which isfairly long in the direction of' its pathv through the rolls. The usualsheet bar, for example, is only around eight inches in length, as used,being cut from a narrow thick bar and ,then turned Aat right angles andfed through the obbing or sheetmill.

. Accordingly invmyprocess I use a wide -thick plate or-it might betermed a slab, and

cross cut the slab by shears to givepieces fwhich have substantialdimension lengthwise, and Ycrosswise have the dimension which yit isdesired to have. in the nal product.

1th my newmill the'pieces are reduced singly and without reheating,which is an economy 1n time and expense, but demands high speedoperation, and accurate fit of the piece, as soon as it gets itspreliminary, reduction, to the remaining rolls of the successive stands.

I find it to be impractical to use sheet bars turned crosswise in myprocess, and can conceive of no practical way/in which a properlyheated, uniform temperature, and'uniform cross section piece can beprovided for a high speed reduction mill of my new type, exceptby somesuch mode I have f described, namely, to provide a succession of Abetween the main rolls 8, 9 and 10a.

'ing a single side' 'guide bar 13 for the piece,

` I show feed tables 11 between the several stands of rolls, 4and preferto make these tables oflskewed driven rollers 12, and havwhich directsit toward the middle of each stand of rolls. ,I

Ishow the lfirst three stands of rolls arranged in tandem, and the lasttwo stands, equally spaced Jfrom the stands preceding them, which willresult in their operating as continuous mill' stands, if the piece islong enough.

' If the operation were slow, at least while l the piece is'thiclntheremightbe a chance Yfor obtaining enough reduction if the mills were likethe plate mill stands of the presentv day, but economy of operationmakes'as one of my chief objectives Aa very 'high speed operation withminimum labor.

If the operation were slow, and the capacity of the mill kept low, itmight'be possible to control the shape of the rolls ofthe severalstands, and permit them torun hot I and attain a greater reduction perpass.

However, the high capacity operation, re- Asul'ting in a rapid heatingof the rolls byl the' great volume of pieces passing between them,requires a cooled vroll mill operation, and accordingly I provide for anample iow of water over the rolls as by means of spray pi es 14.

ith plenty of Water on thez rolls' I- am able to arrive at a desired.controlled vtemperature thereof, which gives me oneyfactor which is'controllable in providing for proper bite of the rolls on the piece. Bydelivering the pieces to .the mill at a uniform temperature anduniformcro section, for any given run, and passing themthrou h at highSpeed without reheating, I'can re y upon definite cross sectional andtemperature characteristics ofthe vpieces in each stand..V

I have discovered asthe principle gov- Verning Afitofa piece to' a'roll' stand in hot.

rolling practice, that the iece will enter the L- ystand and passthrough ll smoothly, `if'the active 'pass Kbetweenthe rolls ofthe stand,as they engage over 1thepiecc is such as to be a little less convex,than the shape of the piece, furnished to the stand, said convexityrunning'lengthwise f the Pass, and Cro/Sgr, wise of the piece. The bestpractice is to reduce the vcontour (cross sectional periphery) of thepiece so as to retain the same or slightly decrease the ,proportionatethickness of its middle as to its edg'es, which as can beobservedrequires more reduction of the thicker than the thinner parts ofa piece in each pass. The mere control of the screw is not enough toinsure proper pass since for required reductions of a piece there are Iqu1te definitel limitations .in screw adjustment, and the piece musthave a required length when finished.

In control `of pass in successive stands of rolls operating on a piece,there are a number of factors of importance, i. e.,'the

original composition, shape, temperature ofthe rolls, the nature, andtemperature of the piece, and the pressure on the rolls in the form ofscrew In building my` mill I provide for the extreme of rigidity formthe rolls of large diameter in`proportion to length, also givingrigidity. By roviding an extremely rigid mill I am ena led to 'controlthe screw on the rolls lin the sev-4 eral stands, to give desiredreductionof pieces passed through singly, and to bring j single piecesdown tol comparatively ine gauge. `YVhengthe housings are springy, the

`natural elasticity of partsrequlres of the screw that it take up all oflthis lelasticity before a reduction can be made on a thin piece, thenthe strain on the bearings of the rolls would be almost as4 eatwhenthere was no piece in them asvif the piece were there, which makesexcessive wear. In a springy, stand of rolls it is ve l accuracy t takeup enough o the spring by turning down the screw, to obtainydeslredreductions." y

The use" of three high stands of rolls, witha small diameter middlelroll, gives more rapid reduction to the piece without sacrifice of thenecessary rigidlty. `The middle roll can be drawn out leaving the. milltwo hig Also the piece is met byI one positively driven roll, i..e., oneof the main rolls Iinstead ofpassing between two idler rolls;

diicult w ith v in the housings, and

as in afour hi h roll stand, with the two' ijniddle vrolls o smalldiameter. Furthermore, thekmultiplication of factors in controlling rollshape when engaging the piece, by use of four rolls, will give greaterdiilicultythan where but three are used.

By description in the foregoing of Aspecial expedients, as being ofprimary nnportance, I do not wish to be taken' as meaning thatequivalent expedients could not be adopted. It is my purpose in theclaimthat follows to state'the invention inherent in my application from itsdifferent aspects, and in the specifications have given a description ofa way of accomplishin without'intentmf limiting the scope of my claim; Rf

the entire objective,

isc

Having thus described my invention, what successive stands of rolls,without reheating,

ciaimas new and desire to secure by Letmaintaining said rolls cold, andproviding ters Patent, is in each stand for enforcing a, transverse 10That process of reducing thick Wide metal convexity on the piece witheach stand en- 5 to thin plates Which consists in furnishing forcing a,less conveXity than the preceding :L series of heated pieces to thickmetal, pass: stand.

ing said metal in single thickness through JOHN B. TYTUS

